Current supercapacitors are made from activated charcoal or carbon aerogels, so extending the concept to other forms of micro- or nano- structured carbon is not a very big leap. The "graphene from graphite oxide using a consumer DVD burner" has shown up in various places before, but it turns out that "graphite oxide" is far from a common or easy-to-prepare (or safe) chemical, so it's not clear that this really makes for a revolutionary discovery in terms of "process." Presumably, this is where "chemical engineering" comes in (as opposed to solid state physics, nano-technology, or chemistry.)
There are still electrical engineering problems. Just because a "capacitor" is theoretically chargeable "instantly" doesn't mean that it is practical to do so. Even with current electric vehicle batteries, you need to get a dedicated high-power outlet installed in order to charge the battery "overnight." A capacitor might charge faster, but that doesn't mean that charger technology, or residential wiring, or the power grid, can keep up with faster charge rates.
Current supercapacitors have FAR less capacity than batteries on either a per-weight or per-volume basis. I can't tell whether graphene caps would change that. Probably not; it would seem to me that storing energy in chemical bonds is always going to be a higher density solution that storing energy by forcing electrons into a "bucket."
I find the steps between "chemistry in a lab process" and "large scale manufacturing" to be wildly incomprehensible. In electronics, there is fairly obvious linear scaling and use of robotics and such; "bigger machines go faster and do more things at once." In chemistry... there is a lot of magic. Conversions between batch processes and continuous processes. Recycling of reagents. Things that go boom... Shudder.
(also, there are all those thin-film processes for solar cells that have been touted as being a step toward "extremely cheap manufacturing" that have not panned out very well.)